From Evidence to Practice: A Behaviourally Informed Multidisciplinary Strategy to Increase Cefazolin Prophylaxis in Joint Arthroplasty Patients with Penicillin Allergy Labels

Background: Cefazolin is recommended for surgical prophylaxis in most patients with penicillin allergy labels (PALs) but concerns over beta-lactam cross-reactivity often limit use. We evaluated a behaviourally informed, multidisciplinary antimicrobial stewardship strategy on cefazolin utilisation among patients with PALs undergoing joint arthroplasty. Methods: Behavioural change frameworks identified determinants influencing perioperative antibiotic prescribing, which guided multidisciplinary antimicrobial stewardship strategy implementation over two phases: (1) department-level advocacy within Orthopaedics and then (2) hospital-wide advocacy. We retrospectively evaluated the strategies among adults with PALs undergoing primary total knee or hip arthroplasty. The primary outcome was cefazolin utilisation over time. Secondary outcomes included perioperative hypersensitivity reactions, surgical site infections (SSIs), and prosthetic joint infections (PJIs). Results: The proportion of patients receiving perioperative cefazolin increased significantly and sustainably over time (p < 0.001), rising from approximately 20% (baseline) to 92.9% (peak). Among 606 patients, 356 and 250 received cefazolin and alternative antibiotics, respectively. Suspected perioperative hypersensitivity reactions were uncommon, mild, and self-limiting (0.8% vs. 2.0%, cefazolin vs. alternative). SSIs and PJIs were similar between groups. Conclusions: A behaviourally informed, multidisciplinary stewardship strategy successfully increased cefazolin use in joint arthroplasty patients with PALs. Similar behavioural frameworks may be adopted to guide the design of other antimicrobial stewardship interventions to drive sustainable practice change.